ROCK CRYSTAL REVERSE INTAGLIO BROOCH, LATE 19TH CENTURY

Collet-set with a domed rock crystal, the reverse carved in intaglio and coloured with a design of a bullfinch on the branch of a plane tree. Reverse intaglio rock crystal jewels became popular from around 1860, initially manufactured by the Belgian artist Emile Marius Prader, and in England most notably by the lapidary Thomas Cook and his student Thomas Bean. These unusual jewels were extremely labour intensive. A miniaturist would paint a design in watercolour on the reverse of a hand polished rock crystal cabochon, and then a specialised lapidary would carve the design in intaglio into the rock crystal. Finally, the intaglio's surface would be painstakingly applied with oil paint in order to faithfully recreate the miniaturist's design, before the back would be sealed and the piece set by a jeweller. So skilful were these miniature designs that in England they were initially assumed to be the work of the renowned contemporary enamel miniaturist William Essex (1784-1869). Though Essex had no involvement in the medium's development, these distinctive pieces became known as 'Essex Crystal', an erroneous name that is still in use today. The present piece, with its design of a bullfinch upon the branch of a plane tree, is representative of the natural themes popular in this medium, and in particular the three-dimensional branch of the plane tree jutting forward into the rock crystal demonstrates the extraordinary heights of technical virtuosity that were achieved by these distinctive jewels.

Unsigned. Diameter approximately 30mm, depth approximately 11.6mm, not including pin fitting. Scratches to metal and rock-crystal surfaces consistent with wear. Carving in good condition, with minor losses to areas of paint, mostly to plane tree fruit and areas of bark. Brooch fitting in good condition, closing securely, with extra safety catch. Gross weight approximately 18 grams. Overall in good condition. For further information please contact the department on +44 (0)207 293 6409. 
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Please note that colour, clarity and weight of gemstones are statements of opinion only and not statements of fact by Sotheby's. We do not guarantee, and are not responsible for any certificate from a gemological laboratory that may accompany the property. We do not guarantee that watches are in working order. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue, in particular to the Notice regarding the treatment and condition of gemstones.
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